Master Closures in Python: A Practical Guide

Learn how closures work in Python with clear-cut examples and take your programming skills to the next level

Photo by Sangga Rima Roman Selia on Unsplash

Have you ever heard of closures in Python but weren’t sure what they were or how to use them? You’re not alone! Closures can be a tricky concept to grasp, but once you understand them, they become a powerful tool in your Python arsenal. This guide will break down closures and show you how to implement them in your code through practical examples.

First things first — what is a closure? Simply put, a closure is a function that has access to variables from its enclosing scope, even after the outer function has returned. Let me illustrate this with an example:

def counter():
    count = 0
    
    def increment_counter():
        nonlocal count
        count += 1
        return count
        
    return increment_counter

my_counter = counter()
print(my_counter()) # Output: 1
print(my_counter()) # Output: 2
print(my_counter()) # Output: 3

In this example, increment_counter is a closure because it has access to the variable count, which belongs to the enclosing counter function. Each time we call my_counter(), it increments the value of count by one and returns the new value. The beauty of using closures here is that…